<template>
  <div class="app-container">
    <!--表单-->
    <el-form :inline="true" class="demo-form-inline">

      <el-form-item>
        <el-select v-model="searchObj.type" clearable placeholder="请选择">
          <el-option label="学员登录数统计" value="login_num"/>
          <el-option label="学员注册数统计" value="register_num"/>
          <el-option label="课程播放数统计" value="video_view_num"/>
          <el-option label="每日课程数统计" value="course_num"/>
        </el-select>
      </el-form-item>

      <el-form-item>
        <el-date-picker
          v-model="searchObj.begin"
          type="date"
          placeholder="选择开始日期"
          value-format="yyyy-MM-dd" />
      </el-form-item>
      <el-form-item>
        <el-date-picker
          v-model="searchObj.end"
          type="date"
          placeholder="选择截止日期"
          value-format="yyyy-MM-dd" />
      </el-form-item>
      <el-button
        :disabled="btnDisabled"
        type="primary"
        icon="el-icon-search"
        @click="showChart()">查询</el-button>
    </el-form>

    <div class="chart-container">
      <div id="chart" class="chart" style="height:500px;width:100%" />
    </div>
  </div>
</template>

<script>
import echarts from 'echarts'
import statistics from '@/api/statistics'
export default {
    data() {
        return {
            searchObj: {
                type: '',
                begin: '',
                end: ''
            },
            btnDisabled: false,
            xData: [],
            yData: [],
            title: ''
        }
    },
    created() {

    },
    methods: {

      // 查询按钮
      showChart() {
        this.queryStaToJsonArray()
      },

      // 图表显示，返回2部分数据，日期json数组和数量json数组
      queryStaToJsonArray() {
        statistics.queryStaToJsonArray(this.searchObj)
          .then(response => {
            this.xData = response.data.dateList
            this.yData = response.data.dataList
            // 当前统计类别
            switch (this.searchObj.type) {
              case 'login_num' : 
              this.title = '学员登录数统计'
              break;
              case 'register_num' : 
              this.title = '学员注册数统计'
              break;
              case 'video_view_num' : 
              this.title = '课程播放数统计'
              break;
              case 'course_num' : 
              this.title = '每日课程数统计'
              break;
            }
            this.setChart()
          })
      },

      // 设置图表
      setChart() {
          // 基于准备好的dom，初始化echarts实例
          this.chart = echarts.init(document.getElementById('chart'))

          // 指定图表的配置项和数据
          var option = {
            title: {
              text: this.title
            },
            tooltip: {
              trigger: 'axis'
            },
            dataZoom: [{
              show: true,
              height: 30,
              xAxisIndex: [
                0
              ],
              bottom: 30,
              start: 10,
              end: 80,
              handleIcon: 'path://M306.1,413c0,2.2-1.8,4-4,4h-59.8c-2.2,0-4-1.8-4-4V200.8c0-2.2,1.8-4,4-4h59.8c2.2,0,4,1.8,4,4V413z',
              handleSize: '110%',
              handleStyle: {
                color: '#d3dee5'
              },
              textStyle: {
                color: '#fff'
              },
              borderColor: '#90979c'
            },
            {
              type: 'inside',
              show: true,
              height: 15,
              start: 1,
              end: 35
            }],
            xAxis: {
                type: 'category',
                data: this.xData
            },
            yAxis: {
                type: 'value'
            },
            series: [{
                data: this.yData,
                // 折线图
                type: 'line',
                smooth: true
            }]
          };

          this.chart.setOption(option)
      }
    }
}
</script>